In the summer of 1879, when my grandmother was a few months old and the potato famine still a living memory, the Virgin Mary appeared to a group of children in the neighbouring village of Knock, in County Mayo in the West of Ireland. The local church soon became a shrine and a place of pilgrimage, where the devout reported miracle cures, resulting from the holy waters arising from the bog. A centenary visit from the Pope, followed by Mother Theresa and the construction nearby of an international airport have assured Knock's status as a major Marian shrine and centre of healing, rivalling continental locations such as Lourdes and Fatima.1
My family links with Knock, which I visited several times as a child, have given me a close familiarity with a healing tradition that both predates modern medicine and continues to thrive alongside it. Though this alternative approach is not included in the 'big five' complementary and alternative medicines (CAM) recommended by the report produced by Christopher Smallwood at the behest of Prince Charles (osteopathy, chiropody, acupuncture, homeopathy, herbalism), it has much in common with these methods.2 There is strong anecdotal evidence of the efficacy of Knock holy water; not only in the sworn testimony of those who have experienced miraculous cures, but also in the accounts of many more patients whose spirits have been lifted and symptoms alleviated. Like other modes of complementary and alternative medicine, spiritual healing Knock-style is not susceptible to sceptical inquiry, its claims resting on divine - and clerical - authority.
There is negligible evidence that any alternative therapy is more effective than placebo. A recent systematic review by Professor Edzard Ernst of two of the methods recommended by Smallwood and Prince Charles for wider recognition within the NHS - chiropractic and osteopathy - found little evidence of efficacy and none of superiority over conventional treatments for a range of complaints (including back and neck pain, period pain, colic, asthma, allergy and dizziness).3 Around half of all patients experienced minor side-effects from manipulation. An earlier report noted that, though the danger of stroke from manipulation is small, in the USA spinal manipulation 'is the number one reason for people suffering from stroke under the age of 45'.4
The drive to integrate CAM with mainstream medical science reflects muddled thinking.5 Not only is there a lack of empirical evidence for alternative therapies, they also lack a coherent theoretical basis - and most, such as homeopathy, are biologically …